No he's not. Jayson Tatum has a good handle / ball security for his size
He can hit "tough" sidestep 3s at a higher rate than Jaylen. He gets to the line at a higher rate than. Jaylen, he's a more prolific scorer than Jaylen and he's a better free throw shooter than Jaylen.
Jaylen is a better, more efficient scorer than Tatum. It sounds like blasphemy but it ain't. Jaylen is also a difficult shot maker, especially on turnarounds and turnaround fadeaways. He's starting to introduce the Jimmy Harden step back too. He's also a 3 level scorer, unlike Tatum who is not a scorer from the midrange. Jaylen is a better driver whether it be scoring on drives, passing on drives to find open teammates or for assists, and committing fewer turnovers / offensive fouls on drives. He also has hit some clutch baskets at the end of close ballgames moreso that Tatum.
Jaylen hustles more than Tatum. He boxes out more. He grabs the tougher contested defensive rebounds than Tatum, the true mark of a good rebounder. He defers more rebounds than Tatum does so the numbers get skewed a lil bit. He contests more shots than Tatum. He usually will defend tougher guys on defense than Tatum. They're both really good on defense and Tatum improved this year but Brown is more of a lockdown corner to Tatum's zone corner / free safety, to use a football analogy.
The team will still defer to Tatum tho. Even Ime. I heard him say a few weeks ago that the C's had two guys who were great shooters in the midrange in Jaylen and Jayson. I was like
cuz Tatum is not good in the midrange. In fact, his fg% from 10-16 feet has decreased every year. His fg% from 16-3P has oscillated. It's 39.7% for his career. His free throw shooting brings his TS% up compared to Jaylen but still not as good.
Ultimately, it comes down to the media and the fanbase. In Boston, the media and fans are mostly white. So they gon gravitate more to the lightskin Tatum, which is understandable. They won't gravitate towards Jaylen. I've heard them talk about Tatum as a "natural" and how Jaylen is an "athlete" and had to "learn the game." None of that shyt is true.
Jaylen, when he's not losing the ball, is one of the most fluid, smooth, explosive athletes in the league. He has a some absolutely nasty in and out, stop and go moves. He is pound for pound the best righty, left handed finisher in the league. He has shot over 70% at the rim 3 years in a row. He has better shooting percentages from the field, the rim and the free throw line in the playoffs than he does in the regular season. As a result, his WS per 48 if u a lytics lover, have increased every year in the playoffs. None of that is true of Tatum. Tatum shoots worse from everywhere in the playoffs, including the field, rim and free throw line.
What it comes down to is Jaylen tightening his handle, which will allow him to get more touches and make more plays, cuz he's a better "pure" passer than Tatum. Tatum is a better playmaker right now cuz he handles it more and is more secure. Jaylen also needs to continue to improve his free throw shooting. He had improved it for 3 years in a row before this year. If he can get up to 80% in the regular season, look the fukk the out.